This invention broadly relates to a new fastener assembly for use in connection with at least first and second apertured workpieces. More particularly this invention relates to an elastomeric grommet-fastener assembly which may be used in fastening the valve cover of an automotive engine into its secured position on the engine head.
Automotive power train designers have had significant problems over the last 5-10 years or longer in reducing engine structural noise, vibration and harshness related to various moving or vibrating components of the under-the-hood engine assembly. For example, past valve cover arrangements for automotive engines have used various types of metal fastener arrangements to hold the valve cover in position on the engine, however, the past fastening means for securing the valve cover have transmitted significant structural noises, vibrations and the like, which it would be desirable to greatly reduce or eliminate altogether. Special fasteners have been used and attempted for this type fastening arrangement in the past but have not been successful.
As one example of the above, a prior art fastener arrangement is shown in U.S. Pat. No. 4,732,519 exemplifying a fastener assembly which has been employed in the past to secure a valve cover on an automotive engine. U.S. Pat. No. 4,732,519 employs wings 28 and 30 which are forged into the fastener shank 22 and a metal sleeve annular bead portion 33 that is smaller than the diameter of a circle defined by the wings 28 and 30 located on the fastener shank 22. The fastener assembly shown in U.S. Pat. No. 4,732,519 has been attempted for usage in the automotive industry since approximately 1986, however, there have been significant problems connected with its usage and application. For example that fastener assembly is cumbersome and difficult to work with because it requires manual assembly of expensive components, and in addition that fastener is difficult and expensive to build because it requires a specialized metal forging operation to make the metal sleeve which contains the wings 28 and 30 on the shank 22, as well as requiring the forming of an annular metal bead portion 33 on its washer member. Accordingly, there has been a long felt need in the art for an economical and efficient fastener assembly which can be suitably used in the securing of valve covers on an automotive engine; and which will also assist in substantially reducing structural noise, vibration, and harshness normally associated with the automotive engine.
The state of the art is indicated by the following cited references: Weidner U.S. Pat. No. Re. 27,085; Hirsch U.S. Pat. No. 765,139; Weber U.S. Pat. No. 793,754; Wehmanen U.S. Pat. No. 2,643,904; Armour U.S. Pat. No. 3,066,568; Scholz U.S. Pat. No. 4,176,437; King U.S. Pat. No. 4,521,147; Wagner U.S. Pat. No. 4,732,519; and Wagner U.S. Pat. No. 4,975,008.
A principal object of the invention is to provide a new and improved elastomeric grommet-fastener assembly for use in connection with at least first and second apertured workpieces.
Another object of the invention is to provide a new fastener assembly for use in securing the valve cover of an automotive engine in proper position while at the same time acting to substantially reduce and/or eliminate the transmission of engine structural noises and vibration.
Another object of the invention is to provide a new and improved valve cover assembly for an internal combustion engine which includes a special elastomeric grommet-fastener assembly technique.
Other objects, features and advantages of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.